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1 • <br /> Phase 2 Soil Sampling of Tidal Channel Alignment:Smith Island Estuary Restoration Project <br /> June 5,2015 <br /> Page 2 of 3 <br /> manage excavated soils and to determine if future aquatic species introduced to this area would be <br /> impacted by residual metals. <br /> Soil Sampling Scope of Work <br /> The purpose of the proposed scope of work is to collect an adequate number of samples so that <br /> lateral and vertical distribution of aerially-deposited arsenic and other metals are understood.Since <br /> there are no historic on-site sources of metals,other than past periodic placement of biosolids <br /> _venlyacross_themiddle.and western gortiono_f_the_site,jton be assumed that all metal <br /> concentrations above background can be attributed to air stack emissions from historic smelting <br /> operations.Consequently,it is reasonable to assume that the lateral distribution of arsenic over the <br /> site is fairly uniform,i.e.,there is no reason to suspect that any one location at the site has a more or <br /> less likelihood of being contaminated than any other location. <br /> Task 1: Soil Sampling <br /> ICF proposes to use manual direct-push soil sampling techniques to collect representative soil <br /> samples.The objective of the soil sampling program will be to collect a sufficient number of samples <br /> over the approximately 50 acre site so that informed decisions can be made on how to best manage <br /> excavated soils,including possible placement of excavated soils into low lying wetlands with <br /> degraded vegetation.Excavation will occur in the dike to construct the breach and in the proposed <br /> tidal channel where soils will be excavated on average to a depth of 5 feet below grade.Some <br /> grading of existing roads and removal of compacted soil from past construction staging areas will <br /> also occur. <br /> Soil samples would be collected within both wetland and upland areas along the alignment of the <br /> tidal channel as depicted in the ICF 60%plans.Details on the proposed sampling plan are presented <br /> below. <br /> Sampling Techniques <br /> The manual sampling technique will involve the use of a bucket auger to remove soils to the sample <br /> target depth.Once the sample target depth is reached a 1.5-inch diameter direct push barrel will be <br /> used to extract subsurface samples into acetate barrel liners.Given the expected composition of <br /> soils at the project site we anticipate that barrel can be pushed at a depth of 5 feet below grade,the <br /> maximum depth we will sample. <br /> Samples collected by this manual sampling technique will be capped,labeled with a unique sample <br /> identification,and placed in an ice-filled cooler while awaiting delivery to an analytical testing <br /> laboratory after all samples are collected.All equipment used for sampling will be decontaminated <br /> between each sample location using an industry-accepted triple rinse technique.All rinse water will <br /> be contained in either drums or 5-gallon buckets and kept on site pending disposal. <br /> For costing purposes we have assumed the waste water will need to be analyzed for standard RCRA <br /> hazard constituents prior to acceptance by the disposal company and will be found to be classified <br /> for disposal as a non-hazardous waste.ICF will coordinate directly for the waste water analysis and <br /> 78 <br />